Test Bench: SB Acoustics’ Satori MW13TX-4 5” TPCD Cone Midbass Driver

TPCD is the acronym for Thin-Ply Carbon Diaphragm, which is essentially the technology developed in Sweden by Oxeon to create a new-generation material with properties that are now well-proven for speaker cones and domes. The Satori MW13TX-4 TPCD cone 5” woofer is the fourth TPCD diaphragm transducer to be explicated in Test Bench, and this one has a substantial feature set, including a single piece bowl-shaped TPCD cone and NBR surround. This article was originally published in Voice Coil, January 2022.

The driver on this Test Bench is from B&C Speakers and clearly designed for professional audio. The 10NW76 was designed for uses in line arrays, small two-way monitors, and as a subwoofer, or as a midbass driver in multiway systems. It uses a proprietary 12-spoke (six double spokes) cast-aluminum frame with a series of cooling vents that allow air to move past the voice coil and across the front side of the neodymium motor assembly. The cone assembly consists of a curvilinear waterproof coated paper cone and dust cap. This article was originally published in Voice Coil, December 2021.

This Test Bench explication focuses on the Dayton Audio Epique MMAG E150HE-44 "full-range subwoofer," in itself an interesting concept. Like its larger E180HE-44 brother in the Epique line, the E150HE-44 is based on the patented Multiple Magnet Air Gap (MMAG) technology invented by Enrique Stiles. The two new Dayton Audio Epique MMAG woofers were designed with direct support by Enrique as an independent transducer engineering consultant, working in conjunction with the engineering team at Dayton Audio. This article was originally published in Voice Coil, December 2021.

This Test Bench article characterizes Eighteen Sound’s AMT200P Air Motion Transformer and accompanying XMT200 6.5” waveguide. This driver is the brand's latest entry into the high-frequency transducer category, specifically designed for the pro sound community. The Eighteen Sound AMT200P includes a rectangular throat with a Kapton diaphragm with a neodymium magnet structure, and is rated for a power handling of 90W AES above 1.2kHz, with a sensitivity of 105dB, and a recommended crossover frequency of 1.2kHz at 48dB/octave. While the AMT200P can be used as a standard planar device it can be also coupled with a dedicated constant directivity horn, the 90°x 20° XMT200, featured in the characterization.

This Test Bench addresses Purifi Audio’s PTT4.0X04-NFA-01 4” midbass, which is very similar to the PTT6.5X reviewed in Voice Coil July 2021, and includes the same constant Sd surround and low magnetic hysteresis motor design. The distinct cone assembly for this driver consists of a flat profile paper cone made with a proprietary fiber mix, a concave dust cap that covers about 90% of the cone surface, plus the addition of a V-shaped edge reinforcing ring glued around the outside rim of the back side of the cone. Compliance is provided by a unique NBR surround, which as in the PTT6.5X surround, deserves to be explored, motivating Vance to discuss it with Purifi’s co-founder Lars Risbo.

While Voice Coil Test Bench reviews only make use of the Large Signal Identification (LSI) data from the Klippel analyzer, the reality is that there is an amazing list of 30 modules available for the KA3 that are seriously valuable for transducer and system development. As space permits, I will be covering a number of these modules in future issue of Voice Coil. The first module in this series is the Time Frequency Analysis (TFA) module. This article was originally published in Voice Coil, October 2021

We're off to a great start in 2022. Starting with details about the promise of Iron Nitride (FeN) magnets, followed by an article about Liquid Injection Molding Silicon for Next-Generation Headphone Surrounds. Next up, James Croft reviews a surround speaker patent granted to Klipsch, and Vance Dickason characterizes the Satori MW13TX-4 TPCD-cone woofer from SB Acoustics and the high-power WF275BD01 10.75" woofer from Wavecor. All articles now available to read online, PDF and print.

We looked at the most-read articles of 2021 in audioXpress.com (including selected articles from Voice Coil magazine), and we created this Top 10 list of news stories and online articles. 2021 expanded slightly on the record-breaking year that was 2020 for audioXpress.com, in terms of number of visits and regular users of the website. Visitors from all over the world returned more often to read the more than 7,700 stories available. Which of the topics and stories published online in 2021 were the most popular? Here are the results!

This Test Bench focuses on Eighteen Sound’s latest ND2T, a 1.4” neodymium compression driver, combined for characterization with the XT1464 elliptical-shaped horn, also from Eighteen Sound. This ultra-compact compression driver features a 2.4” diameter edge-wound voice coil wound with aluminum wire on a non-conducting Nomex former with a proprietary treatment. This assembly drives a field-replaceable pure titanium diaphragm and proprietary tangerine radial phase plug design. This article was originally published in Voice Coil, October 2021.

This Test Bench explication characterizes the 15DS100 15” professional subwoofer from B&C Speakers. This new transducer from the Italian company is a very high power handling design, able to deliver 3kW continuous (1.6W nominal), thanks to B&C's latest generation of very long voice coils - a great asset in applications from discreet PA subwoofers to three-way PA speakers. The B&C 15DS100-4 uses a proprietary 12-spoke cast aluminum frame with cooling vents for the neodymium FEA motor, which uses a 4” four-layer voice coil wound with round aluminum wire on a non-conducting glass fiber former. This article was originally published in Voice Coil, October 2021.